We can also see Amazon selling Chromecast, although, it's not surprising that Chromecast doesn't qualify for Amazon Associates Program Product. I guess, no company would like to make a double loss. But all in all, it's safe to assume, Google and Amazon have come to a peace treaty now.
Why it took 4 years for Google and Amazon to fix this? Well, we don't know for sure. But, Google Stadia and the upcoming Amazon Prime sale definitely have something to do with it.
Updated: October 9, 2021